<?php
/**
 * Created by PhpStorm.
 * User: 氓羽
 * Date: 2018-3-31
 * Time: 17:32
 */
class Person{
    public static $hand = 'hand';
    public static $foot = 'foot';

    public $con = 1;

    public static  function work(){
        echo (self::$hand);
        return "Hello World";
    }
}
class Son extends Person{
    public function play(){
        return parent::work();
    }
}

$aa = new Son();
echo $aa->play();
echo "<hr>";


echo Person::work();